David A. Berntsen

An assessment of grading scales for meibography images.

Purpose: To evaluate the within- and between-reader reliability and the interrelation between 2 methods of grading meibography images. Methods: A video meibography sequence (1200 frames) was captured from 290 patients using near-infrared light (650-700 nm) and a near-infrared CCD camera. One frame was selected for grading by 2 masked readers using 2 scales, where the first reader graded the image on 2 occasions and the second reader graded the image on 1 occasion. The first grading scale was a gestalt assessment (categorically graded), which is an assessment of partial meibomian glands within the image. The second was a count of individual whole glands. Within- and between-reader reliability and concurrent validity between the scales were examined. Results: Within-reader reliability of the gestalt scale was moderate to high (simple κ = 0.78, 95% confidence interval [CI] = 0.71-0.85 and weighted κ = 0.91, 95% CI = 0.88-0.95). Within-reader reliability of individual gland counting was moderate via a 95% limits of agreement analysis (−2.84-2.76 glands). Between-reader reliability of the gestalt scale was fair (simple κ = 0.38, 95% CI = 0.30-0.46 and weighted κ = 0.57, 95% CI = 0.47-0.68). Between-reader reliability of gland counting was fair via a 95% limits of agreement analysis (−4.46-5.08 glands). There was a strong relation between the gestalt scale and gland counting indicating good concurrent validity (Z = −15.15, P < 0.0001). Conclusions: These methods of grading meibography images demonstrate good within-reader reliability and fair between-reader reliability. Responsiveness to change will need to be addressed in future studies.

The effect of overnight contact lens corneal reshaping on higher-order aberrations and best-corrected visual acuity.

Purpose. The purpose of this study is to determine the effect of higher-order aberrations after Corneal Refractive Therapy (CRT) on best-corrected visual acuity (BCVA) and the impact of pupil size on BCVA. Methods. High-contrast (HC) and low-contrast (LC) Bailey-Lovie BCVA was measured in the morning before and after pupil dilation on 20 myopes (mean spherical equivalent -3.11 D ± 0.96 D) under age 40. BCVA was measured again in the afternoon after dilation. Dilated am and pm aberrations were measured using the Complete Ophthalmic Analysis System (WaveFront Sciences). Patients were fit with CRT lenses in each eye. One month after finalizing the lens fit, BCVA and aberration testing were repeated. Average higher-order RMS error (third to sixth order), spherical aberration, third-, fourth-, fifth-, and sixth-order RMS error were calculated at each visit for a 3-mm and 5-mm pupil. BCVA and aberration data were analyzed using a repeated measures analysis of variance. Linear regression was used to describe the relationship between aberrations and BCVA reductions after CRT. Results. Mean refractive error changed by +3.33 D ± 0.96 D. No clinically significant changes were found in HC BCVA post-CRT, whereas LC BCVA reductions of 0.07 logarithm of the minimum angle of resolution (logMAR) (nondilated, p = 0.002) and 0.12 logMAR (dilated, p < 0.001) were found. No additional decrease in HC BCVA was found after pupil dilation, whereas a mean additional decrease of 0.08 logMAR in LC BCVA was found with dilation post-CRT (p = 0.013). Higher-order RMS error increased for both 3-mm and 5-mm pupils (p < 0.0001) and remained stable between measurements. Spherical aberration increased for 5-mm pupils after CRT (p < 0.0001). For a 5-mm pupil, a 0.1-&mgr;m increase in spherical aberration was associated with an additional decrease in LC BCVA after pupil dilation post-CRT of 0.056 logMAR (R2 = 0.382, p = 0.004). Conclusions. CRT results in reduced low-contrast BCVA as a result of increased higher-order aberrations. Higher-order aberrations appear to be relatively stable after CRT. Spherical aberration appears to drive additional low-contrast BCVA losses as pupil size increases.

A Randomized Trial Using Progressive Addition Lenses to Evaluate Theories of Myopia Progression in Children with a High Lag of Accommodation

PURPOSE To compare the effect of wearing, then ceasing to wear, progressive addition lenses (PALs) versus single vision lenses (SVLs) on myopia progression in children with high accommodative lag to evaluate accommodative lag and mechanical tension as theories of myopia progression. METHODS Eighty-five children (age range, 6-11 years) with spherical equivalent (SE) cycloplegic autorefraction between -0.75 D and -4.50 D were randomly assigned to wear SVLs or PALs for 1 year; all children wore SVLs a second year. Children had high accommodative lag and also had near esophoria if their myopia was greater than -2.25 D SE. The primary outcome after each year was the previous years change in SE. RESULTS When the children were randomly assigned to SVLs or PALs, the adjusted 1-year changes in SE were -0.52 D (SVL group) and -0.35 D (PAL group; treatment effect = 0.18 D; P = 0.01). When all children wore SVLs the second year, there was no difference in myopia progression between SVL and former PAL wearers (0.06 D; P = 0.50). Accommodative lag was not associated with myopia progression. CONCLUSIONS The statistically significant, but clinically small, PAL effect suggests that treatments aimed at reducing foveal defocus may not be as effective as previously thought in myopic children with high accommodative lag. Finding no evidence of treatment loss after discontinuing PAL wear supports hyperopic defocus-based theories such as accommodative lag; however, not finding an association between accommodative lag and myopia progression is inconsistent with the PAL effect being due to decreased foveal blur during near work. (Clinical Trials.gov number, NCT00335049.).

Peripheral defocus and myopia progression in myopic children randomly assigned to wear single vision and progressive addition lenses.

PURPOSE To determine the effect of progressive addition lenses (PALs) and single vision lenses (SVLs) on peripheral defocus in myopic children, and to compare the effect of myopic versus hyperopic peripheral defocus on foveal myopia progression. METHODS Eighty-four myopic children aged 6 to 11 years with spherical equivalent (SE) cycloplegic autorefraction between -0.75 diopters (D) and -4.50 D were randomly assigned to wear SVLs or PALs. Aberrometry measurements of the eye and spectacles were made centrally, 30° nasally, temporally, and superiorly, and 20° inferiorly on the retina using a Complete Ophthalmic Analysis System for Vision Research (COAS-VR). The association between peripheral defocus and the 1-year change in central myopia was investigated. RESULTS SVLs caused a hyperopic shift in peripheral defocus at all locations (all P ≤ 0.0003). PALs caused a myopic shift in peripheral defocus in three of four locations measured (all P ≤ 0.01) with the greatest shift superiorly due to the PAL addition (-1.04 ± 0.30 D). Superior retinal defocus when wearing either SVLs or PALs was associated with the 1-year change in central myopia. The adjusted 1-year change in central SE myopia was -0.38 D for children with absolute superior myopic defocus (n = 67) and -0.65 D for children with absolute superior hyperopic defocus (n = 17; difference = 0.27 D; P = 0.002). CONCLUSIONS PALs caused a myopic shift in peripheral defocus. Superior myopic defocus was associated with less central myopia progression. These data support the continued investigation of optical designs that result in peripheral myopic defocus as a potential way to slow myopia progression. (ClinicalTrials.gov number, NCT00335049.).

Study of Theories about Myopia Progression (stamp) Design and Baseline Data

Purpose. The Study of Theories about Myopia Progression (STAMP) is a 2-year, double-masked, randomized clinical trial of myopic children 6 to 11 years of age. STAMP will evaluate the 1-year effect of progressive addition lenses (PALs) compared with single vision lenses (SVLs) on central refraction, peripheral refraction in four quadrants, and accommodative response and convergence. STAMP will also evaluate any changes 1 year after discontinuing PALs. Baseline characteristics of enrolled children are reported. Methods. Eligible children had a high accommodative lag and either low myopia (less myopic than −2.25 diopter (D) spherical equivalent) or high myopia (more myopic than −2.25 D spherical equivalent) and esophoria at near. Children were randomly assigned to wear either PALs or SVLs for 1 year to determine the difference in myopia progression in the PAL group relative to the SVL group. All children will then wear SVLs for the 2nd year to evaluate the permanence of any treatment effect. Complete ocular biometric data are collected at 6-month intervals. Results. Over 17 months, 192 children were screened, and 85 (44%) were eligible and enrolled. Of these 85 children, 44 (52%) were girls, and 54 (64%) were esophoric at near. The mean age (± SD) was 9.8 ± 1.3 years. The right eye mean cycloplegic spherical equivalent refractive error was −1.95 ± 0.78 D. Horizontal relative peripheral hyperopia (30° nasal retina + 0.56 ± 0.59 D; 30° temporal retina + 0.61 ± 0.77 D) and vertical relative peripheral myopia (30° superior retina −0.36 ± 0.92 D; 20° inferior retina −0.48 ± 0.83 D) were found. Conclusions. The baseline data for STAMP are reported. Asymmetry between vertical and horizontal meridian relative peripheral refraction was found. STAMP will use the ocular biometric changes associated with the PAL treatment effect to attempt to elucidate the mechanism responsible for the treatment effect.

Validation of aberrometry-based relative peripheral refraction measurements

Purpose:  To validate aberrometry‐based relative peripheral refraction (RPR) measurements and to examine RPR differences in the nasal and temporal horizontal visual field.

Accommodative Lag and Juvenile-Onset Myopia Progression in Children Wearing Refractive Correction

The relationship between accommodative lag and annual myopia progression was investigated using linear models in 592 myopic children wearing a full refractive correction in the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study. The mean (± SD) age and spherical equivalent refractive error at baseline were 10.4 ± 1.8 years and -2.13 ± 1.24 D, respectively. The mean annual progression of myopia was -0.45 ± 0.32 D, and the mean accommodative lag (for a 4-D Badal stimulus) was 1.59 ± 0.63 D. Neither lag at the beginning nor at the end of a yearly progression interval was associated with annual myopia progression (all p ≥ 0.12). These data suggest that foveal hyperopic retinal blur during near viewing may not drive juvenile-onset myopia progression.

Reliability of grading lissamine green conjunctival staining.

Purpose: To assess the reliability of a lissamine green grading scale for conjunctival images. Methods: A 20-second video clip of the right eye of 288 contact lens-wearing individuals was recorded using a digital slip-lamp camera after instilling liquid lissamine green. A single nasal and temporal still image were selected. A masked reader used the Oxford grading scale to grade the images on two occasions whereas a second masked reader graded each image on 1 occasion. κ statistics and 95% confidence intervals (CIs) were used to determine the within- and between-grader reliability overall and when the sample was stratified by age, sex, contact lens type, and disease severity. Results: There was substantial within-grader reliability for both the nasal (κsimple = 0.69, 95% CI, 0.63-0.75) and temporal (κsimple = 0.73, 95% CI, 0.67-0.79) images. There was moderate between-grader reliability for both the nasal (κsimple = 0.51, 95% CI, 0.44-0.58) and temporal (κsimple = 0.51, 95% CI, 0.44-0.58) images. Age, sex, and contact lens type did not affect within- or between-examiner reliability. There may have been an influence of disease severity on within-examiner reliability, because grading of the temporal images was significantly less reliable in the images with more significant staining. Conclusion: Within- and between-grader reliability of lissamine green staining seems to be at least substantial to moderate. Because the extent of conjunctival staining may influence reliability, this should be considered when studies may include patients with significant staining.

Contact Lenses in Pediatrics (CLIP) Study: chair time and ocular health.

Purpose. Despite several studies that show 8- to 11-year-old children are capable of wearing a various contact lens modalities, parents often report that their eye care practitioner would not fit their child with contact lenses until the child was about 13 years old. We conducted the Contact Lenses in Pediatrics (CLIP) Study to compare contact lens fitting and follow-up between 8- to 12-year-old children and 13- to 17-year-old teenagers. Methods. At the baseline visit, all subjects underwent a contact lens fitting, including visual acuity, a manifest refraction, autorefraction, and biomicroscopy. Subjects then underwent contact lens insertion and removal training, which consisted of talking about contact lens care as well as inserting and removing a contact lens three times. Subjects returned for follow-up visits at 1 week, 1 month, and 3 months, and visual acuity, contact lens fit assessment, and biomicroscopy were performed. The time of the fitting, the insertion and removal training, and each follow-up visit were measured individually and added for a total chair time. Biomicroscopy examinations were conducted according to a standardized protocol. Results. We enrolled 84 children and 85 teens in the study. Of the 169 subjects, 93 (55.0%) were female, 78 (46.2%) were white, 44 (23.3%) were Hispanic, and 28 (17.6%) were black. The mean (± SD) total chair time for children was 110.6 ± 39.2 min, significantly more than 95.3 ± 25.2 min for teens (Student’s t-test, p = 0.003). Most of the difference was caused by insertion and removal training, which lasted 41.9 ± 32.0 min for children and 30.3 ± 20.2 min for teens (Student’s t-test, p = 0.01). The presence of conjunctival staining increased from 7.1% of the subjects at baseline to 19.9% of the subjects at 3 months (&khgr;2, p = 0.0006), but the changes were similar between children and teens. No other biomicroscopy signs increased significantly over the 3-month period. Conclusions. The total chair time for children is approximately 15 min longer than teens, but most of that difference is explained by longer time spent teaching children insertion and removal. Because insertion and removal is generally taught by staff members, the eye care practitioner’s time with the patient is similar between children and teens. Furthermore, neither children nor teens experienced problems related to contact lens wear during the study. Eye care practitioners should consider routinely offering contact lenses as a treatment option, even for children 8 years old.

Visual acuity with spherical and toric soft contact lenses in low- to moderate-astigmatic eyes.

Purpose. To evaluate the visual acuity of myopic, astigmatic eyes, with spherical and toric soft contact lenses. Methods. A randomized, masked, cross-over study was conducted to compare acuity with soft spherical and toric contact lenses on patients with between −0.75 and −2.00 D of refractive astigmatism. A total of 15 patients (30 eyes) were fitted with four brands of spherical and toric lenses (Acuvue Advance, Biomedics 55, Frequency 55, and SofLens 66), in random order. An initial visit was conducted to fit the lenses and an over-refraction (OR) was performed to determine the best prescription. At the measurement visit, patients’ pupils were dilated with 1.0% tropicamide and 2.5% phenylephrine to allow wavefront aberration measurements, and a final OR was performed. A 6-mm aperture was held in front of the eye to measure visual acuity through just the contact lens and the contact lens with the final OR. Acuity was measured monocularly, under photopic and mesopic conditions with high- and low-contrast logMAR charts at distance. Differences in acuity were analyzed using repeated measures analysis of variance. Results. Visual acuity with soft spherical contact lenses was not significantly different between lens brands. For toric contact lenses, acuity was significantly better with Biomedics 55 and SofLens 66 than with Acuvue Advance; and acuity with SofLens 66 was significantly better than with Frequency 55. Low-astigmatic eyes gained between 3 and 5.5 letters of acuity with toric contact lenses vs. spherical lenses; and moderate-astigmatic eyes gained between 8 and 12.5 letters. Conclusions. Both low- and moderate-astigmatic eyes showed improvements in acuity with toric contact lenses. Lens brand had a measurable effect on acuity for toric contact lenses. Further investigation of aberrations induced by contact lens design is warranted to explain the observed differences in visual performance.